1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device and method for driving the same that can reduce power consumption.
2. Discussion of the Related Art
Liquid crystal display (LCD) devices control the light transmittance of pixels in accordance with video signals to display images. Active matrix type LCD devices are advantageous in displaying moving images because of a switching device in each pixel. Thin film transistors (hereinafter, referred to as “TFTs”) are mainly used for the switching device.
LCD devices periodically invert the polarity of data charged in pixels to reduce flickers and residual image defects. The inversion method is classified into a line inversion method in which the polarity of one horizontal line of pixels is opposite to the polarity of neighboring line of pixels, a column inversion method in which the polarity of one vertical line of pixels is opposite to the polarity of neighboring line of pixels and a dot inversion method in which the polarity of a pixel is opposite to the polarity of neighboring pixels in horizontal and vertical line directions.
FIG. 1 is a schematic view of a plurality of pixels illustrating the dot inversion method according to the related art.
Referring to FIG. 1, in the dot inversion method, the polarity of data charged in a pixel is opposite to the polarity of data charged in neighboring pixels in horizontal and vertical line directions. Also, the polarities of the data of the pixels are inverted for each frame Fn-1, Fn.
In order to reduce flickers in both the vertical and horizontal directions and to reduce power consumption, a two dot inversion method is recently suggested and widely used for LCD devices. FIGS. 2 and 3 are schematic views illustrating the two dot inversion method according to the related art. FIG. 4 shows the polarities of data applied to the data lines in the two dot inversion method according to the related art.
Referring to FIGS. 2 to 4, in the two dot inversion method, two pixels neighboring in the vertical direction is treated as a unit of pixels so that the polarity of data charged in two pixels that are neighboring in the vertical direction is opposite to the polarity of data charged in neighboring units of pixels in horizontal and vertical line directions. As in the dot inversion method, the polarities of the data charged in the pixels are also inverted for each frame Fn-1, Fn.
Recently, as the resolution of LCD devices becomes higher, the number of pixels connected to a one horizontal line is increasing. As a result, even with the two dot inversion method, the power consumption of the LCD device is high due to the high driving frequency.